scholarly journals The Microscopic Appearance of Fracture Surface of Each Failure Modes in the Matrix on Gray Cast Iron

2004 ◽  
Vol 53 (8) ◽  
pp. 913-916
Author(s):  
Koichi YAMANAKA ◽  
Hideyuki OGISHI ◽  
Yasumasa OKU
2020 ◽  
pp. 303-312 ◽  
Author(s):  
J.M. Makar ◽  
R. Desnoyers ◽  
S.E. McDonald

Metals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1329 ◽  
Author(s):  
Bingxu Wang ◽  
Xue Han ◽  
Gary C. Barber ◽  
Yuming Pan

In this research, an austempering heat treatment was applied on gray cast iron using various austempering temperatures ranging from 232 °C to 371 °C and holding times ranging from 1 min to 120 min. The microstructure and hardness were examined using optical microscopy and a Rockwell hardness tester. Rotational ball-on-disk sliding wear tests were carried out to investigate the wear behavior of austempered gray cast iron samples and to compare with conventional quenched and tempered gray cast iron samples under equivalent hardness. For the austempered samples, it was found that acicular ferrite and carbon saturated austenite were formed in the matrix. The ferritic platelets became coarse when increasing the austempering temperature or extending the holding time. Hardness decreased due to a decreasing amount of martensite in the matrix. In wear tests, austempered gray cast iron samples showed slightly higher wear resistance than quenched and tempered samples under similar hardness while using the austempering temperatures of 232 °C, 260 °C, 288 °C, and 316 °C and distinctly better wear resistance while using the austempering temperatures of 343 °C and 371 °C. After analyzing the worn surface, abrasive wear and fatigue wear with the presence of pits, spalls, voids, long cracks, and wear debris were the main mechanisms for austempered gray cast iron with a low austempering temperature. However, only small pits and short cracks were observed on the wear track of austempered gray cast iron with high austempering temperature. Furthermore, the graphite flakes were exposed and ground by the counterpart surface during wear tests. Then, the graphite particles would form a tribo-layer to protect the contact surface.


2011 ◽  
Vol 194-196 ◽  
pp. 1803-1806
Author(s):  
Yong Hong Fu ◽  
Li Bin Niu

A kind of centrifugal casting plus in situ techniques of fabricating iron-based composite coating reinforced by tungsten carbide (WC) particles was developed. The experimental results show that the reinforcing particles were generated by reaction between dissolved tungten wires and carbon from gray cast iron molten. The composite coating mainly consists of primary WC carbides, some fine secondly WC carbides as the reinforcing phase and pearlite accompanied by negligible graphite flakes as the matrix. Compared with the unreinforced gray cast iron, the in situ synthesized WC particles can enhance the ultimate tensile strength and decrease elongation rate of the composite coating. Fracture morphology reveals that fracture mode of composite coating is brittle and ductile mixed fractures, the fracture mechanism of the composite is not only related with the introduction of reinforcement but also with the reduction of graphite flakes in the matrix


2019 ◽  
Vol 16 (2) ◽  
Author(s):  
Amin Suhadi ◽  
Seodihono

Production technology of metal casting industry in Indonesia needs to be improved, especially in the manufacturing of spare parts and box engine made of gray cast iron which has various wall thick such as dove tale construction. Microstructure of gray cast iron is influenced by cooling rate during casting, chemical composition and melting treatment process (inoculation). The part which has the thinnest thickness has the fastest cooling therefore, the grain boundary is smaller compared to other section. As a result this part has highest hardness and difficult to be machined. This research is conducted to solve this problem by modifying melting and solidification treatment process. The research starting from micro structure analysis, composition and mechanical properties tests on the product, and then conducting modification treatment through Taguchi method approach. Experimental results obtained show that the best level settings to control factors which affect to the uniformity of the microstructure and mechanical properties in gray cast iron is the addition of seed inoculation super ® 75, as much as 0.25% with the method of inoculation material entering into the Transfer Ladle.Teknologi produksi pada industri pengecoran di Indonesia masih membutuhkan perbaikan terutama dalam pembuatan komponen mesin perkakas dan peralatan pabrik yang terbuat dari besi tuang kelabu yang mempunyai variasi ketebalan yang besar seperti konstruksi ekor burung (dove tale). Pada pengecoran, struktur mikro dari besi tuang kelabu sangat dipengaruhi oleh kecepatan pendinginan, komposisi kimia dan proses perlakuan pada logam cair (inokulasi). Bagian yang mempunyai ukuran paling tipis mempunyai kecepatan pendinigan paling tinggi karena itu ukuran butirnya jauh lebih kecil dari bagian lain, akibatnya bagian ini mempunyai kekerasan lebih tinggi dan sulit dilakukan pengerjaan mesin. Penelitian ini bertujuan untuk memperbaiki hal ini yang terjadi pada dove taledengan cara memodifikasi proses perlakuan pada cairan besi dan proses pendinginan. Penelitian dimulai dari analisa struktur mikro, pengujian komposisi kimia, pengujian sifat mekanis pada produk kemudian dilakukan modifikasi menggunakan pendekatan metode statistik Taguchi. Hasil penelitian menunjukkan bahwa pengaturan terbaik yang dapat diperoleh untuk mendapatkan keseragaman struktur mikro dan sifat mekanis pada pengecoran besi tuang kelabu adalah penambahan seed inoculation super ® 75, sebesar 0.25% dengan metode pemasukan inokulasi kedalam Ladle pengangkut logam cair.Keywords: carbon, micro structure, hardness, inoculation


Alloy Digest ◽  
1973 ◽  
Vol 22 (2) ◽  

Abstract MEEHANITE GF-20 is a gray cast iron designed principally for high machinability and is used where strength is not an important factor. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear strength as well as fracture toughness and fatigue. It also includes information on corrosion resistance as well as casting, heat treating, machining, joining, and surface treatment. Filing Code: CI-39. Producer or source: Meehanite Metal Corporation.


Alloy Digest ◽  
2020 ◽  
Vol 69 (9) ◽  

Abstract ISO 185/JL/225 is an intermediate-tensile-strength gray cast iron that has a predominantly pearlitic matrix, and a tensile strength of 225–325 MPa (33-47 ksi), when determined on test pieces machined from separately cast, 30 mm (1.2 in.) diameter test bars. Compared with the lower strength gray cast iron grades, ISO 185/JL/225 contains lower carbon and silicon contents, while still maintaining excellent thermal conductivity, damping capacity, and machinability. This datasheet provides information on composition, physical properties, tensile properties, and compressive strength as well as fatigue. It also includes information on heat treating. Filing Code: CI-73. Producer or source: International Organization for Standardization (ISO).


Author(s):  
Eduard Riemschneider ◽  
Ilare Bordeasu ◽  
Ion Mitelea ◽  
Ion Dragos Utu ◽  
Corneliu Marius Crăciunescu

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